The present invention relates to a method for a communication device in a wireless communication system, and more particularly, to a method of handling a radio resource for a communication device in a wireless communication system.
IEEE 802.11 is a set of media access control (MAC) and physical layer (PHY) specification for implementing wireless local area network (WLAN) communication in the unlicensed (2.4, 3.6, 5, and 60 GHz) frequency bands. The standards and amendments provide the basis for wireless network products using the unlicensed frequency bands. For example, IEEE 802.11ac is a wireless networking standard in the 802.11 family to provide high-throughput WLANs on the 5 GHz band. Significant wider channel bandwidths (20 MHz, 40 MHz, 80 MHz, and 160 MHz) were proposed in the IEEE 802.11ac standard.
When a first station (e.g. a router or an access point) communicates with a second station, the first station may adaptively rearrange radio resource of communications. For example, the first station may change a channel bandwidth from 80 MHz to 40 MHz and support rates to mitigate interference to other radios or adjust a number of spatial streams (i.e. the number of antennas) used for the communications. When the first station intends to rearrange the radio resource, the wireless networking standards in the 802.11 family specify the first station to notify the second station of the changed radio resource.
After notifying the changed radio resource, however, the first station cannot ascertain whether the second station successfully receives the notification and accordingly follows the radio resource rearrangement. If the second station does not obey the changed capability, the communications between the first station and the second station would fail. Furthermore, the first station would not acknowledge the communication failure because payloads of the transmitted packets from the second station cannot be decoded.